Question

George took a nonstop flight from Dallas to
Los Angeles, a total flight distance of 1,233
miles. The plane flew at a speed of 460 miles
per hour for the first 75 minutes of the flight
and at a speed of 439 miles per hour for the
remainder of the flight. To the nearest minute,
for how many minutes did the plane fly at a
speed of 439 miles per hour?

Answer 1

It is given in the question that,

George took a nonstop flight from Dallas to Los Angeles, a total flight distance of 1,233 miles. The plane flew at a speed of 460 miles per hour for the first 75 minutes of the flight and at a speed of 439 miles per hour for the remainder of the flight.

Let for x hours, the flight travelled with a speed of 439 miles per hour .

So we have,

$460* \frac{75}{60} + 439*x = 1233$

$575 + 439x =1233 \\ 439x = 1233 - 575 \\ 439x = 658 \\ x = \frac{658}{439} hours  $

And to convert it in minutes, we have to multiply by 60. And on doing so, we will get

$x = \frac{658}{439}*60 =approx \ 90  \ minutes$

Answer 2

The plane flies at a speed of 439 miles per hour in 90 minutes.

Given

George took a nonstop flight from Dallas to Los Angeles, a total flight distance of 1,233 miles.

The plane flew at a speed of 460 miles per hour for the first 75 minutes of the flight.

And at a speed of 439 miles per hour for the remainder of the flight.

Let, x be the flight traveled with a speed of 439 miles per hour.

What is the relationship between time and speed?

The relation between time and speed is defined as the product of distance and time.

$\rm Distance= \dfrac{Speed}{Time}\\\\Speed = Distance \times Time$

Therefore,

The plane flew at a speed of 460 miles per hour for the first 75 minutes of the flight.

$\rm Speed = Distance \times Time\\\\Speed = 460 \times 75\\\\Speed = 34500$

And x be the flight traveled with a speed of 439 miles per hour is.

$\rm Speed = Distance \times Time\\\\Speed = 439 \times x\\\\Speed = 439x$

Therefore,

The time taken in minutes did the plane fly at a speed of 439 miles per hour is;

$\rm 34500+439x=1233\\\\ \text{Multiple by 60 to convert into minutes}\\\\439x= 1233- \dfrac{34500}{60}\\\\439x=1233-575\\\\439x=658\\\\x=\dfrac{658}{439}\\\\x=\dfrac{658}{439}\times 60\\\\x=90 \ minutes$

Hence, the plane flies at a speed of 439 miles per hour in 90 minutes.

To know more about Speed time relation click the link given below.

https://brainly.com/question/14969352